Final answer:
The primary differentiation between the fast and slow solar winds is their density. The fast solar wind is less dense than the slow solar wind, with a density of about 10 protons per cubic centimeter compared to about 100 protons per cubic centimeter for the slow solar wind.
Step-by-step explanation:
The primary differentiation between the fast and slow solar winds, apart from the speeds at which they travel, is their density. The fast solar wind is less dense than the slow solar wind.
Fast solar winds have a density of about 10 protons per cubic centimeter, while slow solar winds have a density of about 100 protons per cubic centimeter.
This difference in density is due to the different mechanisms that produce the two types of solar wind. The fast solar wind originates from coronal holes, where the magnetic field is open and allows particles to escape more easily. The slow solar wind, on the other hand, originates from regions with closed magnetic field lines, which restrict the escape of particles and lead to a higher density.